s390: remove unneeded variables

This patch remove unneeded variables used to store return values.

These issues were detected with the Coccinelle script:
scripts/coccinelle/misc/returnvar.cocci

[heiko.carstens@de.ibm.com]: make qeth_l[2/3]_stop() return void

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 70eb2f61..a1aaa36 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2158,10 +2158,8 @@
 	return card ;
 }
 
-static int qeth_l3_stop_card(struct qeth_card *card, int recovery_mode)
+static void qeth_l3_stop_card(struct qeth_card *card, int recovery_mode)
 {
-	int rc = 0;
-
 	QETH_DBF_TEXT(SETUP, 2, "stopcard");
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
 
@@ -2196,7 +2194,6 @@
 		qeth_clear_cmd_buffers(&card->read);
 		qeth_clear_cmd_buffers(&card->write);
 	}
-	return rc;
 }
 
 /*